1. Field of the Invention
The invention is directed to a torsional vibration damper, especially for clutches in motor vehicles.
2. Description of the Prior Art
A torsional vibration damper is known from German reference DE 36 28 774 A1 which has a first flywheel mass on the drive side and a second flywheel mass which is rotatable relative to the first flywheel mass and is connected via a torsional damping device. At least one of these flywheel masses is provided with a grease chamber containing a viscous medium for at least partial accommodation of the torsional damping device. Openings provided for mounting purposes extend axially in the wall of the drive-side flywheel mass, which wall faces a drive. Each of these openings can be closed by a closure in the form of a sealing cap which can be inserted into the opening so that viscous medium contained in the grease chamber of the flywheel mass cannot exit from the flywheel mass at this location.
The disadvantage in this type of construction of the closure is that a tight seal is no longer ensured when the closure is opened and then closed again several times. Another problem, arising especially when transporting the torsional vibration damper and during subsequent assembly, is that the closure, inasmuch as it is included along with the torsional vibration damper in a loose fashion, could be lost since it is usually only inserted into the associated opening after the grease chamber is filled with viscous medium.